<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>两栏布局2</title></title>
</head>
<style>
  * {
    margin: 0;
    padding: 0;
  }
  html,body{
    height: 100%;
  }
  .box1{
    width: 200px;
    height: 100%;
    background-color: yellow;
    position: absolute;
    left: 0;
    top: 0;
  }
  .box2 {
    height: 100%;
    margin-left: 200px;
    background-color: blue;
  }
</style>
<body>
    <div class="box1"></div>
    <div class="box2"></div>
</body>
</html>